Mass Effect: Alien Force
by edboy4926
Summary: Shepard receives the unexpected help of two beings from another dimension. How will the arrival of the Tennysons affect the ME Universe? F-Shepard/Joker, Ben/Gwen
1. Arrival

**Disclaimer- **I do not own Ben 10 or Mass Effect.

**A/N- **This is my second attempt at writing and according to the site this will be the first Ben 10/Mass Effect crossover. So Enjoy. Excuse the grammar, English is my second language.

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**Title- Mass Effect: Alien Force **(title might change)

**Chapter 1- Prologue **

**Location- AU Ben 10 Universe **

"Kevin, are you sure this will work?" Asked 40 year-old Ben Tennyson to his best friend Kevin Levin, who was working on activating an alien artifact, which looked like two long arms with an empty orb between them; that he found while digging around the earth for energy signatures.

"Of course it will work." Kevin said.

"You said that the last time we attempted to do this with another weird artifact that you found." Ben said.

"Don't worry about it. By the way where is your wife?" Kevin asked.

"She is right now busy, thought I did not tell her where were." Ben said.

"You did not tell her? Why?" Kevin asked curious about it.

"If she knew we were attempting to activate an unknown alien artifact without her, she would probably kill the both of us for trying to activate it." Ben said.

"Yeah, you're right about that." Kevin said as he pressed one final button and the artifact started to activate, the rings around the orb started to move and the orb began to glow blue.

"Yes I did it." Kevin said.

"Okay so you managed to turn it on. So what does it do?" Ben said.

"_What does it do indeed?" _A female voice asked behind them.

Both Ben and Kevin suddenly became stiff at hearing that voice. They both turned around to see a purple floating being, which by its face, it looked very pissed off.

"Hi sweetie. How are you?" Ben said in a nervous tone.

The being floated down to the floor and in a bright purple light transformed into a red haired human female.

"How am I? Well one moment I am saving the city from another of Charmcaster's attacks, then when I get home I don't see my husband anywhere and since there was no emergency at that moment, the only thing that crossed my mind on where he was being with his best friend doing something possibly stupid, AGAIN." A very pissed off Gwen Tennyson said to Ben.

"Okay I am sorry I did not tell you. Kevin called that he found this and he wanted an extra set of eyes with him, just in case something bad happens." Ben said.

"What he said." Kevin said pointing at Ben.

Gwen looks at them for a few moments and sighs. "Fine. Since you two did not completely activated this thing before I got here, I will let this slide, but I am sticking with you two while you examine this thing." Gwen said. This causes both Ben and Kevin to relax a bit.

"So Kevin, what do you think this is?" Gwen asked as she got closed to the object.

"Don't know. From what readings I have been able to gather from it, the orb and the arms are made from two separate and unknown elements. The arms' metal is apparently very strong, while the orb's is giving out some sort of energy, who appears to be little of it left inside the orb." Kevin said while typing behind his computer.

"Well Kevin, from what I am sensing, it's giving out what appears to be dark energy. Thought it feels different from other the regular type of dark energy in this universe I have felt." Gwen said as she touched the object. Then all of a sudden, the object started to light up and a field started to appear around Gwen.

"What the hell?" Gwen said as she tried to leave the field but for some reason couldn't. She even transformed to escape but couldn't leave either.

"_Ben, Kevin. I can't get out."_ Gwen yelled.

"Kevin stop this." Ben yelled at him.

"I can't, the object is releasing its remaining energy, and I can't stop it." Kevin said.

Ben then transformed into **Chromastone** and ran to the Gwen, when he touched the field, it blasted him back. He got up and fired a ray at the field but did not break it. Ben then transformed into **Big Chill **and became intangible and managed to enter the field, but when he tries to leave, he cannot.

"Dammit I am stuck, and for some reason I can't change to any form." Ben said.

The field started to act up around the couple and then it looks like they are catapulted upward in an instant. The orb then loses its color and shuts down.

"Gwen, Ben!" Kevin yells as he realizes that his friends are now gone.

"Dammit, what just happened?" Kevin said as he examined the data of what happened.

A few moments later, three sets of light appear behind Kevin. When he looks behind him, he is shocked at whom he sees. The ones who just appeared where Verdona and Max Tennyson; Azmuth and Professor Paradox.

"Kevin what happened? There was a huge energy spike coming from here." Max asked.

"I don't know. I found this artifact in the middle of the desert and then I called Ben to help me with it. After a while, I managed to start it up and then Gwen appeared. When she got near the object, it enclosed her inside a weird energy field. She tried to get out of it, but she couldn't, even in her Anodite form. Ben first tried to use his Chromastone form to enter but it couldn't get though and then fired a laser blast at it, it did not break. He then turned to Big Chill and using his power entered the field but he couldn't not get out nor change his form. A few moments later, it looked like they were catapulted upward and then they were gone. I checked the scans, and whatever that element inside the orb was, it's now depleted, the object won't work." Kevin said.

"This is bad. From the looks of this, this object appears to be a teleporting one. To where it ends, we cannot be for certain." Azmuth said.

"Paradox, you probably know where they went right?" Kevin asked.

"Unfortunately, I do not know. For some reason, I did not foresee this event come to pass. Right now, any future that involved those two have ceased from my vision. I cannot say for certain if they somehow ever return." Paradox said.

"Wait; can Gwen teleport from virtually anywhere?" Kevin asked.

"Sorry Kevin, but while it is true an Anodite is able to do this, Gwen cannot since she only took 15 years of training. While she can stay indefinitely in her Anodite form, she cannot do certain things, among those able to teleport to other dimensions. She can probably teleport a maximum of one planet to another. I can teleport to other dimensions, but without an exact location, it would take me forever searching for them." Verdona said.

"So what are we supposed to do?" Kevin asked.

"The best we can do for now is research the object in detail. We should also try to see if we can find any of the unknown element to power it up and try to find them that way." Azmuth said.

Kevin turned to the object and spoke.

"Ben, Gwen. I do not know where you two are, but we will try everything in our power to get you two home. At least you two are together." Kevin said.

* * *

**Location- AU ME Universe, Presidium**

This meeting was a complete waste of time, Shepard thought to herself. An hour long discussion with the Council and the bloody blind idiots, minus Anderson, who believed her completely; did not believe her Reaper/Collector story, even when she brought Mordin, a respected former STG member, with proof of the Collectors' actions. The only good thing to come out of it is that they reinstated her Spectre status. Right now she was looking toward the lake, trying to calm down. The night cycle of the Presidium started an hour ago, so few people were in the presidium right now. Mordin and Garrus were checking some things in the stores that were still open.

'At least for this one moment, peace and quiet. The fake stars in the ceiling, the silence of being alone, the Prothean Relay activating, the …. Wait, THE PROTHEAN RELAY ACTIVATING!' Shepard came out of her daze when she realized that the relay was activating. She quickly got up her seat and went running toward the relay.

'Dammit, the last time someone used this, it was Saren leading an army of Geth to take control of the Citadel. You think they move the damn thing. Just hope that for once something good comes out of there.' She though as she prepared her weapon, as she waits for whatever comes out of the relay.

The relay's light increases and from the spinning core, two figures come out and land on their feet a few feet in front of Shepard. The light from the relay dies out.

Shepard looks carefully at the two new comers. One looked like humanoid blue insect with butterfly wings, while the other looked like a humanoid female, by the way the body looked like, but was purple and what appeared to be her hair was glowing pink and moving. From what Shepard could tell from the aliens' faces, they were surprised at what just happened. Then both looked at her and for a few moments stayed quiet and then the blue one spoke, thought what he or she said surprised Shepard.

"Hello." The blue alien spoke in English.

'What the heck? Did the blue one just said hello in English?' Shepard thought.

"Yeah, um, would you mind telling us where we are? We kind of got catapulted from where we were and apparently landed here." The blue alien said.

Shepard was still in shock. She then took a moment to recollect herself and asked the blue alien what it said.

"Um, what did you just say?" Shepard asked.

"_He asked where we are."_ The purple alien spoke, also in English.

"Well, you are right now in the Presidium, in the center of the Citadel. Thought from the looks of it, you don't know what the Citadel is, do you?" Shepard asked, as she lowered her gun, but still kept it in her hand.

"No we do not know. Like we said, we just got sent here by accident by a similar object back there. We do not want to cause any trouble." The blue alien said.

Shepard took a few moments to think of what to do. She then decided what to do next was risky but better than the alternative.

"Okay, look this place it's not the best place to talk. We should move to a private location before we continue to talk. Could you please follow me?" Shepard said.

The two aliens look at each other for a few moments and then back at Shepard. The blue alien spoke.

"We will follow you for now, but try anything funny, and you will regret it." The blue alien spoke.

"You have my word. Let's move." Shepard said as she started to move quickly toward the embassies, with the two aliens, who she then realizes, both are flying right beside her.

"You can fly?" Shepard says.

"_Of course we can. Have you never seen someone fly?"_ The purple alien said smiling.

"Not unless you count floating jellyfish." Shepard said.

"Floating jellyfish? Never seen that type of alien." The blue alien said.

"Let's get to where we need to be before someone sees us." Shepard says as she opens a communication line with her two squadmates and Councilor Anderson, telling them to meet her at Anderson's office as soon as possible.

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**Flashback- a few minutes ago**

One moment, Ben and Gwen feel like they are shot out of a cannon into space, then they land on their feet in an unknown place. When they look around the area, they notice a person in front of them, but when they see the person's face, it shocks them greatly. The person in front of the couple looked exactly like Gwen, the only difference being that the person's hair was short.

{Gwen, the person in front of us looks like you. Where the hell did we land?} Ben said to Gwen thought their mental link.

{Knowing our luck, we probably landed in an alternate universe.} Gwen said.

{Let's ask her.} Ben said.

{Okay. Go ahead.} Gwen said.

"Hello." Ben said. This seems to shock the woman in front of them a bit.

"Yeah, um, would you mind telling us where we are? We kind of got catapulted from where we were and apparently landed here." Ben said.

"Um, what did you just say?" The woman asked.

"_He asked where we are."_ Gwen said.

"Well, you are right now in the Presidium, in the center of the Citadel. Thought from the looks of it, you don't know what the Citadel is, do you?" The woman said, as she lowered her gun, but still kept it in her hand.

"No we do not know. Like we said, we just got sent here by accident by a similar object back there. We do not want to cause any trouble." Ben said.

"Okay, look this place it's not the best place to talk. We should move to a private location before we continue to talk. Could you please follow me?" The woman said.

Ben and Gwen look at each other for a few moments, talking mentally between them.

{Should we trust her?} Ben asked.

{While you know I can't read minds, except yours; unless I am touching them physically, I can sense her intentions and hers is saying she is being honest. So yes, I believe we can trust my look alike.} Gwen said.

{Ok.} Ben said.

"We will follow you for now, but try anything funny, and you will regret it." Ben said.

"You have my word. Let's move." The woman said as both Ben and Gwen followed her by flying next to her.

**End flashback**

End Chapter 1

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**A/N- **Hope you like this. I know it is short and maybe simplified but I am trying my best. In the next chapter I will mention the limits on both Ben and Gwen's powers. Once again, sorry for the grammar.

I will like to mention that I might post this story in both the crossover section and the Ben 10 and Mass Effect sections, this way people can find the story. Depending on which section receives the most reviews, I will leave it there and the rest I will delete them.

Please review, but no flames.


	2. Powers

**Disclaimer- **I do not own Ben 10 or Mass Effect.

**A/N- **Okay, this is not a chapter, still working on it, but here are the limits of the Ben and Gwen's powers and description in this story, better than nothing.

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I. Ben- Master Control activated. However, due to traveling to another reality thought the relay, connection to the Codon Stream is low; this results in Ben currently only having access to 10 of his forms along with their ultimate forms, the rest they will unlock as the story continues. Expect Ben to use his Omnitrix to fix the problems of certain aliens and humans.

Ben looks like Ben 10,000 version from the episode _Ken 10_, including his omnitrix, which looks like a gauntlet.

List of active alien forms (cannon forms that do not have ultimate forms, I might create OC forms for them or leave them without one)-

1. Big Chill- Ultimate Big Chill

2. Grey Matter

3. Upgrade

4. Diamondhead

5. XLR8

6. Way Big- Ultimate Way Big

7. Four Arms

8. Swampfire- Ultimate Swampfire

9. Jetray

10. Suggestion? (NO Eon, Anodite or Alien X)

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II. Gwen- she looks like Gwen 10,000 version from the episode _Ken 10_. She does not have the Charms of Bezel. At the age of 19, she went on to train with her grandmother to control her powers, but after 15 years, she left in a hurry to help Ben fight off a powerful alien. Her grandmother told her while her training was incomplete, she could resume anytime she wanted. She can stay in her Anodite form indefinitely without losing herself. However she cannot do certain things and is limited in some.

Powers she has- (this list comes from the Ben 10 Wiki)

1. Mana Manipulation (limited)

2. Flight

3. Telepathy (limited to her husband only and physical touch)

4. Teleportation (limited)

5. Mana Absorption

6. Space Survivability

7. Telekinesis

8. Living Being Sensing

9. Object Creation (limited)

10. Healing living things (limited)


End file.
